Loss of Ammonia Monooxygenase Activity in Nitrosomonas europaea upon Exposure to Nitrite
AUTOR(ES)
Stein, Lisa Y.
FONTE
American Society for Microbiology
RESUMO
Nitrosomonas europaea, an obligate ammonia-oxidizing bacterium, lost an increasing amount of ammonia oxidation activity upon exposure to increasing concentrations of nitrite, the primary product of ammonia-oxidizing metabolism. The loss of activity was specific to the ammonia monooxygenase (AMO) enzyme, as confirmed by a decreased rate of NH4+-dependent O2 consumption, some loss of active AMO molecules observed by polypeptide labeling with 14C2H2, the protection of activity by substrates of AMO, and the requirement for copper. The loss of AMO activity via nitrite occurred under both aerobic and anaerobic conditions, and more activity was lost under alkaline than under acidic conditions except in the presence of large concentrations (20 mM) of nitrite. These results indicate that nitrite toxicity in N. europaea is mediated by a unique mechanism that is specific for AMO.
ACESSO AO ARTIGO
http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=106612Documentos Relacionados
- Inhibition of ammonia monooxygenase in Nitrosomonas europaea by carbon disulfide.
- Ammonium Limitation Results in the Loss of Ammonia-Oxidizing Activity in Nitrosomonas europaea
- In vitro activation of ammonia monooxygenase from Nitrosomonas europaea by copper.
- Mechanism-Based Inactivation of Ammonia Monooxygenase in Nitrosomonas europaea by Allylsulfide
- Sequence of the gene coding for ammonia monooxygenase in Nitrosomonas europaea.
